title: Overproduction of free radical species in embryonal cells exposed to low intensity radiofrequency radiation.
abstract: OBJECTIVE
  Long-term exposure of humans to low intensity radiofrequency electromagnetic radiation (RF-EMR) leads to a statistically significant increase in tumor incidence. Mechanisms of such the effects are unclear, but features of oxidative stress in living cells under RF-EMR exposure were previously reported. Our study aims to assess a production of initial free radical species, which lead to oxidative stress in the cell.
  
  
  METHODS
  Embryos of Japanese quails were exposed in ovo to extremely low intensity RF-EMR of GSM 900 MHz (0.25 µW/cm2) during 158-360 h discontinuously (48 c - ON, 12 c - OFF) before and in the initial stages of development. The levels of superoxide (O2·-), nitrogen oxide (NO·), thiobarbituric acid reactive substances (TBARS), 8-oxo-2'-deoxyguanosine (8-oxo-dG) and antioxidant enzymes' activities were assessed in cells/tissues of 38-h, 5- and 10-day RF-EMR exposed and unexposed embryos.
  
  
  RESULTS
  The exposure resulted in a significant persistent overproduction of superoxide and nitrogen oxide in embryo cells during all period of analyses. As a result, significantly increased levels of TBARS and 8-oxo-dG followed by significantly decreased levels of superoxide dismutase and catalase activities were developed in the exposed embryo cells.
  
  
  CONCLUSIONS
  Exposure of developing quail embryos to extremely low intensity RF-EMR of GSM 900 MHz during at least one hundred and fifty-eight hours leads to a significant overproduction of free radicals/reactive oxygen species and oxidative damage of DNA in embryo cells. These oxidative changes may lead to pathologies up to oncogenic transformation of cells.
authors.affiliation: R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of Ukraine, Kyiv 03022, Ukraine.
authors.forename: A
authors.initials: A
authors.lastname: Burlaka
authors.forename: O
authors.initials: O
authors.lastname: Tsybulin
authors.forename: E
authors.initials: E
authors.lastname: Sidorik
authors.forename: S
authors.initials: S
authors.lastname: Lukin
authors.forename: V
authors.initials: V
authors.lastname: Polishuk
authors.forename: S
authors.initials: S
authors.lastname: Tsehmistrenko
authors.forename: I
authors.initials: I
authors.lastname: Yakymenko
mesh_terms: D000818:Animals; D040421:Cell Phone; D004625:Embryo, Nonmammalian / Q000528:radiation effects*; D005609:Free Radicals / Q000009:adverse effects*; D018384:Oxidative Stress / Q000502:physiology*; D011784:Quail; D011846:Radio Waves / Q000009:adverse effects*; D017382:Reactive Oxygen Species
chemical_list: D005609:Free Radicals; D017382:Reactive Oxygen Species